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Interstellar Flight: Perspectives and Patience

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Re: Interstellar Flight: Perspectives and Patience

#171

Post by nradov »

thechao wrote: post #129
pfdietz wrote: post #75

Earlier quoted context omitted.

However, travel at 0.1c is not needed for the Fermi Argument to bite. Much slower speeds would allow a colonization wave to sweep a galaxy in time << the age of the universe.

Even at .0006c (our current tech), the galaxy would be filled with (weakly self propagating) robotic probes after just 750 million years. Unless extremely long lived self-propagating probes just ... die out ... that implies no aliens older than 750 million years from our galaxy. It implies no aliens from the nearby galactic neighborhood within 3 billion years. That kind of implies we're all alone. I have three wild-e…

Long-lived self-propagating probes are probably impossible. Even out in deep space, mechanisms eventually decay. Building in redundant systems or automated repairs doesn't allow you to cheat the inevitable increase of entropy in that closed system.

Re: Interstellar Flight: Perspectives and Patience

#172

Post by nradov »

usuallyalurker wrote: post #79
krunck wrote: post #16

The comment by Benjamin Stockton on the article page is spot-on: >I just wonder if humanity’s adventurous nature is leading us away from a proper focus on the sustainability of our civilization, our specie, and our fragile planetary environment? But we still need spaceflight at least for planetary defense against asteroids, mining asteroids(so we don't have to mine Earth), etc.

Not only is that comment a false dichotomy (we can both explore space and make humanity more sustainable at the same time), it also presumes that space exploration and sustainability are at odds with one another and not synergistic. Humans, simply by existing on Earth, have a huge and often negative impact on the environment. If we could somehow shift the human population off Earth, either by terraforming planets (li…

It's silly to think that eliminating human impact on Earth's environment is a positive goal. What's the point? Humans are literally part of the environment. (That doesn't mean we should cause wanton damage.) Even if it was possible to live in space I would stay right here, and I make no apologies for my impact.

Re: Interstellar Flight: Perspectives and Patience

#173

Post by lofaszvanitt »

silverquiet wrote: post #165
lofaszvanitt wrote: post #140

Everyone suffers from the sci-fi delusion. We can't solve the problem of large-scale wildfires (sending helicopters and planes to drop water on forest fires is not a viable solution) and we can't even do large-scale terraforming on our own Earth. We have to use containers to transport liquids and solids from one place to another. We cannot control the weather, yet people fantasize about travelling into space. It's de…

I would say worse than that, we are doing the opposite of large-scale terraforming to create a planet that will be rather inhospitable towards the end of this century and even less so in the centuries that follow. I think the sci-fi delusion is a hold over from a better time; the heyday was probably the 50's-60's when scientific progress seems like it was much greater and was actually able to translate into benefits…

Yeah, and nobody cares, nobody seems to notice, seemingly people who have the power to steer things the right way are totally lobotomized. It's just like in Cyberpunk, where the power couple's brain is getting rewired by "entities", because they go against the flow.

Re: Interstellar Flight: Perspectives and Patience

#174

Post by tuatoru »

CJefferson wrote: post #144
imoreno wrote: post #109

With Alpha Centauri being only 4 light years away, interstellar travel seems almost feasible. But then you consider all the inconvenient details, and realize such a journey would have to take hundreds, maybe thousands or even more years on top of some incredible advances in rocket tech. If you go to something like Trappist (40 ly) at 0.01c (very optimistic), it's not just that everyone you know will be dead when you…

I used to often hear people joke that because of Moore's law, there was no point running any computation which would take longer than 4 years, as you'd instead be better to wait 2 years for computers to double in power, then run your problem then. Interstellar travel probably has a similar problem, even if you have an engine that can do 0.1c, you have to be sure in 5 years you won't have one that can do 0.2c, or that…

In addition to nradov's point: double your speed, quadruple the blast energy of collisions along the way. Interstellar space (in galaxies) is not as empty as we could wish.

And the relativistic mass equation imposes a very lower upper bound. Light is slow.

Re: Interstellar Flight: Perspectives and Patience

#175

Post by trhway »

modo_mario wrote: post #120
trhway wrote: post #30

Earlier quoted context omitted.

Our civilization has been driven by expansion. Without it we'd probably collapse into a neurally-connected well-organized ant colony without need for further technological/social/economic progress (which would naturally select/cull out corresponding features in our brain). And, i'd guess that is possible one of the forms of the Great Filter stopping many civilizations. At 53 and good health, i'm contemplating that my…

Why would we not chase technological progress without increasing our proverbial footprint? We're not starting to inhabit new bodies of land for a long time now. We're slowing down our footprint growth among those in the most developed places but chasing new technologies hasn't slowed down accordingly.

Not a full answer, just a minor comment.

>We're not starting to inhabit new bodies of land for a long time now.

Last century has been aviation - start of the expansion into the 3rd dimension - and later - space.

Re: Interstellar Flight: Perspectives and Patience

#176

Post by RandomBacon »

troyvit wrote: post #156
dakial1 wrote: post #137

Earlier quoted context omitted.

I love science fiction because they usually try to play these scenarios in a somewhat feasible future. The 3 Body Problem series (more specifically the 3rd book) goes well into what it would take for humanity to be interestellar even without lightspeed or wormholee tech. Avoiding spoilers it would basically be through hibernation and/or generational ships. Which basically implies of losing all ties to earth and anyon…

I've been reading some sci-fi by Kate Elliott lately. While she gets around large distances with the usual FTL tech of sci-fi, in-system space battles hew a little more to physics, so that you get situations like, "Crap! The bad guys fired all their missiles at us! We have sixteen hours to decide what to do ...." Fun stuff. I bet you're right about emergency situations. On top of that, people have been getting on boa…

I'm reading the sci-fi ExForce series by Craig Alanson. There is jumping (wormholes) and speed of light restrictions where lightseconds, lightminutes, lighthours come in to play. What you see (position of enemy ships) might not be true anymore.

Re: Interstellar Flight: Perspectives and Patience

#177

Post by rakejake »

baxtr wrote: post #124
imoreno wrote: post #109

With Alpha Centauri being only 4 light years away, interstellar travel seems almost feasible. But then you consider all the inconvenient details, and realize such a journey would have to take hundreds, maybe thousands or even more years on top of some incredible advances in rocket tech. If you go to something like Trappist (40 ly) at 0.01c (very optimistic), it's not just that everyone you know will be dead when you…

Maybe not humans, what about robots though? I recently read this in an interview with Juergen Schmidhuber: > Of course, such life-like hardware won't be confined to our little biosphere. No, variants of it will soon exist on other planets, or between planets, e.g. in the asteroid belt. As I have said many times in recent decades, space is hostile to humans but friendly to suitably designed robots, and it offers many…

Or humans with their consciousness uploaded to a silicon or other substrate.

Of course, this is in the realm of science fiction but so is interstellar travel.

Greg Egan's Diaspora has a fantastic treatment of interstellar travel - it involves sending copies of your consciousness to different spaceships traveling to different destinations. On arrival, a preset program will verify if the planel/galaxy is worth waking up to. If not, the clone is terminated.

If more than 1 clone wakes up in a hospitable environment, then you have a problem of two copies of yourself separated by light years.

Re: Interstellar Flight: Perspectives and Patience

#178

Post by db48x »

rakejake wrote: post #177
baxtr wrote: post #124

Earlier quoted context omitted.

Maybe not humans, what about robots though? I recently read this in an interview with Juergen Schmidhuber: > Of course, such life-like hardware won't be confined to our little biosphere. No, variants of it will soon exist on other planets, or between planets, e.g. in the asteroid belt. As I have said many times in recent decades, space is hostile to humans but friendly to suitably designed robots, and it offers many…

Or humans with their consciousness uploaded to a silicon or other substrate. Of course, this is in the realm of science fiction but so is interstellar travel. Greg Egan's Diaspora has a fantastic treatment of interstellar travel - it involves sending copies of your consciousness to different spaceships traveling to different destinations. On arrival, a preset program will verify if the planel/galaxy is worth waking u…

In Diaspora that wasn’t considered to be a problem. Merging two individuals was almost automatic once you’d both decided to do it, and everyone participating in the Diaspora had decided ahead of time whether they wanted to sync back up at the end of it and merge. Also, it was fun that different individuals chose different conditions for waking up, and some stayed awake for the whole trip, or even all of them. Good book.

Re: Interstellar Flight: Perspectives and Patience

#179

Post by db48x »

nradov wrote: post #170
nosianu wrote: post #121

Earlier quoted context omitted.

> Send a computer Those age too. Especially out there without the earth's shields. If you make one that lives longer than a human it's already quite the feat, add only a bit more radiation, it only gets worse. Computers are much worse with failures than brains too. The nice thing about biological systems is the self-assembly from tiny molecule parts. Worst case, you can create a closed system with birth/death renewal…

The notion of a general-purpose molecular assembler or nanofactory appears to be a pure fantasy. We don't even have a theoretical approach to making that happen.

That’s not entirely true. Drexler’s books contain quite a few solutions to nanoscale engineering problems, though not for all of the problems. He designed and characterized a nanoscale mechanical system for separating CO₂ from the air, stripping the oxygen from it, then using the carbon atoms to build tiny blocks of diamond, then using the tiny diamond blocks to build macroscale objects under computer guidance.

Re: Interstellar Flight: Perspectives and Patience

#180

Post by Teever »

sorcerer-mar wrote: post #141
Teever wrote: post #138

Earlier quoted context omitted.

What sort of things do you think are necessary to change for this to happen?

"this" == produce political will to protect the environment at the expense of industry? Not too sure! Probably one part is to disabuse people of the notion that we have alternatives available if only we could just dedicate more brainpower to space travel. The real answer is to eliminate the tradeoffs through scientific innovation. As mentioned elsewhere, the real way to protect earth (and our species) is to produce b…

Do you think that humans will ever colonize other bodies in the solar system, or build large scale artificial habitats that house hundreds of thousands of people?

If so, when do you think this will start to occur? 50 years from now? 100? 200?

If not, why not?

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